Detectives interrupted a heroin deal and arrested three people, including a Fall River woman who had two children with her, Quincy police said.

Angela J. Tantillo, 26, was arrested outside the IHOP restaurant on the Parkingway shortly before 3:30 p.m. Wednesday. Police have been investigating Tantillo, whose nickname is Coco, for several months, believing she was regularly coming to Quincy to sell drugs.

Detectives were waiting for her Wednesday when she drove into the city in a Jeep with a 10-year-old girl and 5-year-old boy in the back seat.

Police said they watched her sell heroin to two men outside of the restaurant and that when they approached her, she told them: “I never sell drugs with kids in the car. I’m just trying to help my cousin.”

She had 10 bags of heroin tucked in her bra and two bags in her purse, Quincy police said. In all, she was carrying 16 grams of heroin, several needles and $2,290 cash, they said.

She was charged with drug trafficking and two counts of child endangerment.

The two men she allegedly sold heroin to – Michael J. Quigley, 23, of 303 West St., Weymouth, and Michael H. Browne, 23, of 10 Haviland St., Quincy – were both charged with drug possession. Quigley was also charged with driving with a suspended license.

The state Department of Children and Families took the two children and planned to turn them over to relatives.